Acoustic distance measurement based on phase interference between transmitted and reflected waves

Abstract

The distance to talkers and objects is very important information for both hands-free speech interfaces and nursing-care robots. However, conventional distance measurement methods cannot measure short distances because the transmitted wave, which has not attenuated sufficiently by the time the reflected waves are received, suppresses the reflected waves for short distances. Therefore, we have proposed an acoustic distance measurement (ADM) method based on interference between the transmitted and reflected waves, which can measure distance even in a short range. In this presentation, we explain principle of the ADM method, and various studies. In the proposed method, the arbitrary audible sound with wideband is emitted as the transmitted wave with a loudspeaker, and the transmitted wave is recorded with a microphone. Thus, we can estimate the distance to a target with single loudspeaker and single microphone. Also, the localization of a target can be achieved using single loudspeaker and multiple microphon...